Apparatus for surface treating small objects



Oct. .12, 1948. A. KECK APPARATUS FOR SURFACE TREATING SMALL OBJECTS 2Sheets-Sheet 2 Filed May 6, 1944 FIG. 5

' FIG. 6

IN VEN TOR.

ANDREW KEGK ATTORNEY Patented Oct. 12, 1948 APPARATUS FOR SURFACETREATING SMALL OBJECTS Andrew Keck, Gahanna, Ohio, assignor to Our--tiss-Wright Corporation,

a corporation of Dela- Application May 6, 1944, Serial No. 534,468

2 Claims.

This invention relates to an apparatus for surface treating smallobjects and may be availed of with particular advantage in applyingfinishing and protective coatings to washers, rivets and the like.

When, for example, objects such as washers are to be surface treated bythe application of a coating of paint, it is current practice to applythe paint in spraying or dipping operations. The application of thepaint in a spraying operation is objectionable because the washersusually have surfaces of such contour or which are so located withrespect to one another, or both, that some of such'surfaces escape thepaint spray, particularly when the washers are painted in mass or batchquantities. When the dipping method of painting is employed, the washersare immersed in the paint and then hung to drain and dry. During thedraining and drying operations, globules of paint frequently accumulateon their undersides. Such grounds may interfere with the intended use ofthe washers by preventing them from lying flat. Moreover, when thewashers are painted in mass or batch quantities, they may adhere to oneanother and when this occurs and they are separated they are improperlyor incompletely coated.

The principal object of the present invention, therefore, is to overcomethe above objections, this object contemplating the application of thetreating medium to the objects in such a manner that all exposedsurfaces will be completely and uniformly treated.

A further object is to prevent the objects being treated from adheringto one another and to prevent localized accumulations of the treatingmaterial.

Other and further objects and advantages will be apparent from thefollowing description, reference being had to the accompanying drawingswherein preferred embodiments of apparatus for carrying out the methodare shown.

In the drawings:

Figure 1 is a perspective view of apparatus for carrying out the method,a portion of the apparatus being broken away to show the constructionand arrangement of its various parts;

Figure 2 is a sectional view taken on line 2--2 of Figure 1;

Figure 3 is a fragmentary sectional view taken on line 3-3 of Figure 2;

Figure 4 is a view in section showing the treating apparatus suspendedwithin a paint tank;

Figure 5 is a view in section of the preferred form of apparatus forcarrying out the method;

pass through it;

Figure 6 is a sectional view taken on line 6--6 of Figure 5;

Figure 7 is a view' in section of another form of apparatus for carryingout the method; and

Figure 8 is a sectional view taken on line 8-8 of Figure 7.

I have found that quantities of small objects such as washers, rivetsand the like may be rapidly and uniformly coated by dipping them in aliquid bath of the coating material and then, after removing them fromsuch bath, directing a gaseous medium against them in such a manner thatthey are caused to traverse a prescribed path and during a part of theirtravel are elevated by the gaseous medium. When such objects areelevated and suspended by a gaseous medium, they will constantly changetheir positions. The said medium thus acts against all surfaces toeffect a uniform distribution of the previously applied coating materialwhile evaporating the solvents employed in connection with suchmaterial. The coating, therefore, will be uniformly distributed over theobjects, will remain of a uniform thickness during the drying operation,and will be dried rapidly.

In Figure 1 of the drawings, there is shown one form of a device bywhich the method of my invention may be carried out. The devicecomprises a cylindrical container H which is closed at one end by aperforated bottom l2 and at its other end by a lid or cover M. A tubeI5, attached to the sidewall of the container, extends from, adjacentthe perforated bottom upwardly through the top of the container. Thelower end N5 of the tube is formed to provide a jet for directing asheetlike flow of gas into the container circumferentially, parallel to,and adjacent the perforated bottom l2. A manually operated valve H isconnected to the outer end of the tube l5 and is used to control thequantity of gas, which in this instance is air, admitted to the tubefrom a suitable source (not shown) through a supply tube H3. The valvei1 is preferably a three-stage control, that is, it is designed so thatit may be adjusted to a position in which it permits a large quantity ofair to it is adjustable to a second position in which the flow of air isreduced, and to a third position in which the flow of air is cut oil.The purpose of this three-stage valve will be fully set forthhereinafter. The cover l4 fits the container tightly and is cut out at{9 to provide an opening through which the tube l5 extends. While it ispreferred to extend the tube along the inside wall of the container, thedevice may be constructed in any suitable manner so that the airdischarge jet causes the air to enter the container as previouslydescribed.

In operating my apparatus, I first introduce into the container aquantity of the objects which are to be painted and which, if necessary,have been first degreased. The cover is then placed on the container.For the best results thequantity of objects introduced into thecontainer at any one time should not exceed two-thirds the totalcapacity of the container, the remaining space being utilized to permitthe necessary free movement of the objects during the drying operation.The container is held in an upright position and the objects therein areimmersed in the coating material by lowering the container into onecompartment of a tank 20 (Figure 4) which contains a bath of the paintwith which the objects are to be coated. When the container is in thebath,

the paint flows through the perforated bottom l2, into the container tocompletely cover the objects. After the objects have been immersed, thevalve I! is opened to its low-stage and the air entering the containercauses the objects to be thoroughly agitated. Agitation of the objectswhile they are immersed in the coating material insures that they cannotremain in a stacked condition and that all of the surfaces thereof willbe covered, Preferably, the flow of air through the jet is nowinterrupted and the container is elevated above the bath and suspendedfrom the edge of the tank, as indicated in dotted lines, by a supportingbracket 2| which is suitably. secured to, and forms a part of, thecontainer.

This operation permits the excess paint to drain from the objects andcontainer back into the tank. After the objects have drained, but beforethe paint thereon begins to dry, the container is removed from above thebath and is hung bythe bracket 2| in the other compartment of the tank,as indicated, and the valve I 1 is opened to its high-stage; Thesheet-like, high-velocity stream of air entering the container adjacentits'bottom keeps the objects in continuous motion, thereby causing anyexcess paint still remaining on them to be removed. The air impart tothe mass of objects in the container and as the objects pass the jet,the air lifts and supports them while turning them. Thus all surfaces ofthe objects are uniformly subjected to the drying action of the airwhileat the same time. the paint adhering to such surfaces is uniformlydistributed.

The air is permitted to flow until the coating on the objects hascompletely dried. The openings in the bottom of the container providefor the escape of the exhaust air and any excess paint removed from theobjects by the air.v

In Figures 5 and 6, there is shown another device for carrying out thesurface treating operation, which device may be preferred because it iscapable of accommodating a greater quantity of objects and becausecollision between the objects during their treatment is minimized. Thisde vice comprises a cylindrical container 25 having an invertedconicalbottom 26 with an air jet 2'! in the tip thereof. A valve Ila. isconnected to the lower end of the jet 21. An open ended tube 28is'supported centrally and vertically within the container by bolts 29.A cover 30, including a centrally disposed deflector 3| and an outerdepending skirt 32, tightly fits the top of the container. The deflectoris preferably cone-shaped and of wood or other cushioning material. Theskirtextends downwardly outside the container and forms a deflector forexhaust air which may s a rotary motion 7 escape through outlet ports 33which are formed in the container near the top thereof. The length anddiameter of the inner tube 28 is such thatit and the container form apair of chambers 34 and 35 which are interconnected by passages 36 and31, The device is provided with a bracket 38 by which it may besupported from a vertical panel or by the side of the paint tank 20.

This device is used only for drying the coating material upon theobjects. In using it, the objects are first dipped in the coatingmaterial and drained, and prior to hardenin of the coating material onthe objects, the latter are placed in the container. The cover is thenfitted securely to the container and the valve Ila is opened. The

jet 2'! is positioned to direct a stream of air upwardly and centrallythrough the inner chamber 34.: The deflector 3| breaks up the air streamand the exhaust air is discharged from the container through theopenings 33 being deflected down:- wardly by the skirt 32. The. airoutlets arepreferably positioned as shown inthe drawings but theirlocation is not critical. They may, for example, be formed in the cover.The cone shaped bottom 26 forms a receptacle 39 which directs theobjects therein toward the center of the container where they are pickedup by the air stream issuing from the jet 2! and are blown upwardlythrough the chamber 34, directed outwardly by the deflector, andreturned by gravity through the. outer chamber 35 to the receptacle 39so. that they may again be picked up by the air stream to start anew thecycle described. The device will operate without the inner tube 28 butits use is highly desirable because it minimizes collisions between therising and descending objects.

In Figures 7 and 8,.a more'simplified form of device is shown. In thisembodiment the casing is provided by a pair of cooperating sections 40and 4|. The said sections are secured together by a central bolt 42 andin chamber. A jet 43 having a valve l 1b extends into the casing throughthe section 40. and directs a stream of air into the device at the lowerside of the drying chamber and circumferentially of the annular Wallthereof. The air 7 is directed against the objects in such manner as toelevate them and while they are elevated to turn them, thereby exposing'all of their surfaces to the drying and coating-distributing action ofthe gaseous medium. The apparatus is highly efiective and enables the.objects to be coated rapidly, titles.

While the invention is described in connection [with an apparatus forpaintin objects, it is to be only and that the invention may be availedof with equal advantage in treating objects which are intended to beimpregnated or impregnated and coated. s

I claim as my invention:

1. .Apparatus for use objects of the character described, comprising aprovide an annular dry- I V entering the V drying chamber is thusadapted to cause the obeconomically and in mass or batch quanunderstoodthat this is by way of illustration in coating manufactured containerinto which said objects are introduced, said container having aperforated bottom through which coating material containing a liquidsolvent may be introduced into the container to coat said objects andmay thereafter drain to remove excess material from said objects, andmeans for directing a jet of a gaseous medium into the container in suchmanner as to elevate said objects and thereby increase the effectivenessof the gaseous medium in evaporating the solvent of the coating materialon said objects.

2. Apparatus for coating manufactured objects such as washers comprisinga first container for a coating material containin a liquid solvent andsecond container into which said objects may be introduced, said secondcontainer having a perforated bottom wall and being adapted forimmersion in a body of said coating material in said first container,said perforated bottom wall permitting excess coating material to drainfrom the objects when the second container is removed from the coatingmaterial in said first container, and means for directing a jet of agaseous medium into the second container in such a manner as to elevatesaid objects and thereby increase the eifectiveness of the gaseousmaterial in evaporating the solvent of the coating material.

ANDREW KECK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

